FragmentTabHost中的setup（）无法应用于

Question

我正在尝试创建一个由tablayout组成的片段，所以我使用的是FragmentTabHost，但是代码中的setup（）方法给出了如下错误 -

  public class PayFrag extends Fragment  {
    private FragmentTabHost mTabHost ;
    View mRoot;
    TabHost tabHost;
     @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,  Bundle savedInstanceState) {

    mTabHost = new FragmentTabHost(getActivity());
mTabHost.setup(getActivity(),getChildFragmentManager(),R.layout.payfrag);

代码中的

lastline会出现错误

我甚至更新了gradle中的android.support-v4 - 这是我的模块gradle

 apply plugin:     'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion '21.1.2'

    defaultConfig {
        applicationId "com.example.sairav.app3"
        minSdkVersion 17
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),        'proguard-rules.pro'
       }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.1.1'
    compile 'com.android.support:support-v4:22.1.1' 
}